Abstract: White carbon black was prepared and sodium tripolyphosphate was by-produced by double-reactor green-process phosphoric acid deposition method.The end-point of reactor I was controlled at pH=9 and temperature=70 ℃;The end-point of reactor II was controlled at pH=4 and temperature=90 ℃.The physical and chemical index testing showed that the performance of white carbon black product has reached the quality standard of rubber ingredients.Furthermore,the DBP absorption value was 2.06-2.74 cm<SUP>3</SUP>/g and nitrogen absorption surface area was 206-313 m<SUP>2</SUP>/g,which reached Class A standard.Reverse cycle and intermittent five-washing filter technology was adopted.Therefore,it was conducive to the recovery of phosphate,to save water and reduce energy consumption.It is confirmed by practical production that this technology had stable running,simple operation,small environmental pollution, and the green process was fully realized.